The effect of temperature on the diffusion length and the scattering cross section of thermal neutrons in graphite

The effect of heating graphite on the diffusion length and effective scattering cross section of thermal neutrons was investigated. It was established that in the 15–350 °C range the diffusion length changes mainly in accordance with the law 1/v for the absorption cross section. The slight deviation from this law is due to the increase of 0.5 mb/deg in the scattering cross section with an increase in temperature.     

Assessment of irradiation response of WWER-440 welds using samples taken from Novovoronezh unit 3 and 4 reactor pressure vessels

The results of the study on Novovoronezh unit 3 and 4 (NV NPP-3 and 4) reactor pressure vessel (RPV) radiation embrittlement measured using subsize impact specimens (5×5×27.5 mm³) fabricated from samples taken from the corresponding RPV walls are presented. The post-irradiation annealing effectiveness and the embrittlement kinetics of Novovoronezh unit 3 and 4 RPV welds under re-irradiation are discussed. Ductile-to-brittle transition temperatures (DBTT) obtained using standard Charpy (TT^10×10) and subsize impact (TT^5×5) specimens of trepans cut out from Novovoronezh unit 2 RPV are compared. A new relation between TT^10×10 and TT^5×5 has been developed.     

Artificial protein vaccines with predetermined tertiary structure: application to anti-HTV-1 vaccine design

A successful approach to the development of a safe and effectivesynthetic vaccine requires that different B and T cell epitopesof the infectious agent be included in the vaccine construction.In this paper we suggest a new approach to vaccine design inthe form of an artificial protein with a predetermined tertiarystructure (PTS vaccines). Based on B and T cell epitope properties,we substantiate the possible use for vaccine construction ofone well-known protein spatial motifthe four-a-helix bundle.Antigenk determinants of cellular immunity (amphipathic a-helkes)and humoral immunity (flexible hydrophilk loop regions) areused as blocks for vaccine design. General principles of PTSvaccine construction have been applied to anti-HTV-1 vaccinedesign.     

Effect of peridural block on the adrenal cortex function after operations on the biliary tract

In patients operated upon with the use of peridural blockade the concentration of 11-OCS in blood plasma does not exceed the normal values both during surgery and in the immediate postoperative period. In patients operated upon under conditions of the routine combined narcosis an increased secretion of corticosteroids was observed.     

Investigation of the flow distribution in the grouting system and joint when rendering dams monolithic

Conclusions The electric-hydrodynamic analogies method, based on the similarity scales set out, allows determination of the main flow conditions in the joint and grouting system, at the same time facilitating the study of the joint grouting process. The authors’ investigations represent only one particular aspect of the problem. The modeling procedure has to be improved in regard to flow conditions and types of circulating liquid. For a truer appraisal of the grouting process, i.e., taking into account irregular placing of the grout in the joint and in the tubes of the grouting system, a study has to be made of the conditions governing settling out of cement from the grout. The cement settling out process is difficult to simulate and it has therefore to be studied on a full-scale rig. Considering that the area of the grouting map can be several hundred square meters, this type of experiment is fairly difficult. However, a knowledge of the flow paameters for the whole map obtained on the basis of electric modeling, can, in the opinion of the authors, provide a study for cement-settling on a fragment of grouting map of much smaller dimensions. The data obtained regarding variation of the hydraulic resistance of the slot and pipe, taking into account settling out of the cement, allow transformation of the hydraulic gradient field to be followed during grouting, in addition to prognosis of the settling of cement over the whole area of the map and in the pipes of the grouting system. Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 1, pp. 17–21, January, 1968.